Condensation in an old exhaust flue

Hello,
Our house is a late 1950's split-level with an addition. In the original part of the house, in the basement, we have a furnace that vents into a brick chimney.
We've recently removed a washer and dryer that were next to the furnace, and noticed water dripping from the foundation under the the chimney, even when there hasn't been rain for days. We checked the outside of the chimney, and its also wet where the brick meets the foundation.
The bottom of the chimney has a small access door. I opened it and the bottom felt damp. There is a pipe in the chimney, it looks and feels like it might be clay or something like that. Before turning on the furnace tonight I felt the pipe and it was dry. Then I ran the furnace for a couple of hours and then stuck my hand into the "clay" pipe in the chimney, and I could feel water on the inside of the pipe.
My questions are:
1) is this condensation normal?
2) what is the proper or normal way to handle it?
Thanks,
Steve
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You say the house is late 50's....how old is the furnace? The bricks on the outside...is there a white colored residue around the pointing?

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Sorry, I knew I forgot some info. The furnace is a Heil and we put it in about 5-6 years ago. I very much doubt its high efficiency - IIRC we paid about $1800 and that included installing it in a different location in the room.
Also, we had a gas water heater that shared the same flue until a few months ago.
The bricks inside, and the bottom of the foundation (where it meets the floor) have white residue.
S

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Yes, that condensation. It's bad. You can get a liner that may solve your problem. Ideally quit using the chimney as a vent and install a dedicated vent. If you need a new furnace then consider going to a 90+ efficiency unit that can be vented with pvc pipe.
Furnaces that vent via the chimney or metal vent pipe need to keep the exhaust heat high enough so that the water does not condensate before it is completely out. It is hard to do in a chimney since they often stick up above the house pretty far. The efficiency of furnaces was pretty low when you house was built so a lot more heat went up the chimney. It was probably not a problem then.
mrsgator88 wrote:

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If I put in a liner, should it be open on the bottom, or will it have a drain pipe like the high eff. ones? My furnace is about 5-6 years old, so I hoping to get more use out of it before replacing it. Thanks,
S

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Agreed. Get a liner. You probably want to let a pro to install it. It's a bit of work. And you don't want to mess up when it comes to your furnace.
The furnace you bought 5 or 6 years ago is still much more efficient than the one made in the 50s. Obviously the exhast is no longer hot enough to keep the water from condensing before it reaches the top. Continuous water condensation will ruin your chimney.
mrsgator88 wrote:

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You have to size the chimney liner to the appliance or appliances that are using the chase (chimney) ...A chimney might have 1-2-3 or 4 chases in it. With different heating equipment for each or combined. My advice would to get a license company to evaluate the situation and install a liner. The negative side of this is...the pointing will go bad if it hasn't already, the bricks will crumble from within and destroy the chimney all together. Another sign is wet plaster inside of the chimney wall...if the wall is paneled....pull the paneling...I bet you see water seeping through. I have seen alot with people who have tried to shortcut the situation. 99% of all 80% AFUE furnaces need liners......if it's a gray area.....it gets a liner

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On 6 Nov 2006 04:46:37 -0800, "jamesgangnc"

WTF?? You're quite the brainiac. Bubba

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Well, it's not rocket science.
Bubba wrote:

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